The present invention relates in general to a coupling, and in particular to a coupling for removably connecting a rod such as for example a winding core for a roll of a web-like material to a driving shaft in a roll processing machine whereby the end portion of the rod has a noncircular cross section provided with a longitudinally directed flat surface and being insertable into a coupling socket formed on the face of the driving shaft and having a contour of its inner wall complementary to the cross section of the noncircular end portion.
In textile and paper processing industries a web-like material is usually wound up on winding rods to form rolls of fabric or of a paper web. In processing such web rolls a device is known from the German patent 917,552 including a so-called tilting bearing having a coupling socket for which a relatively large tolerance is necessary. This large tolerance of the coupling socket is required due to the fact that a plurality of different winding rods has to be applied always to the same driving shaft of the machine and consequently the tolerance is defined by the largest and the least accurate coupling end of the winding rod. For this reason, however, in transferring rotary moments from the driving shaft the rod is subject to additional movements and to a corresponding wear. In addition, the shape of the tilting or snap bearing always sets limits to the applicability of a particular coupling end of the winding rods.